While there would still be people willing to pay I suspect the suscription base will drop dramatically. 
http://www.amazon.com/gp/bestsellers/2013/videogames/ref=zg_bs_tab_t_bsar#1

I know amazon is a very small portion of the market but I think the results are staggering enough to prove a point.

A year of xbox live is the number 1 and number 2 best selling product on amazon for the year(Digital and Retail).
A year of PSN is number 69. The difference in sales is staggering.

On the other hand simple point cards seem to be fairly even between the two systems. Playstation number 3 and 6.  While microsoft has 4, 8, 15, 23.

What I'm trying to say is despite Playstation having a fairly equal marketshare on Amazon based on digital purchases(point cards), xbox live gold is ridiculously more popular than playstation plus. The vast majority of people are paying only to play online.

And yes I think the xbox would have sold quite a bit better had it added free online multiplayer when PSN service improved. The majority of gamers on these systems are not playing exclusive games save for Halo in America and Gran Turismo in Europe. So free online is a huge bonus when all you want to play is CoD, Assassin's Creed, and the yearly sports franchises. Though the increased sales probably wouldn't have negated the loss of suscription revenue.

Party chat requires Gold and was always an XBL feature. Whether or not some other console came out years later and added it is irrelevant to the question asked in the thread.

If people were that dead set against paying for XBL, the service would have never taken off in the first place.

Oh so you can Party Chat on your Vita without being on PSN? That's news to me...

Its a locked feature that depends on system capabilities free or not.

Of course you need online, but since Sony struggled to add it to the PS3 we learned later that it is a feature based on hardware specs being dedicated to its existence and certain amounts of power being freed up to realize its existence.

People who say would still pay are Netflix users, of course.

No, it's because of the business model they're using.

Gold subscribers subsidize Free member subscribers. 

Conversely, originally Sony had subsidized PSN for all members, however with PS+ subscribers now they are subsidizing the free services of PSN.
 

Well, no it wasn't.  Party Chat was a featured added to Xbox LIVE with the original Xbox a year or two after XBL was launched, then disappeared with the Xbox 360.  It later reappeared two years later on the Xbox 360 with either the Spring or Fall 2007 update.

There was a big kerfuffle about it missing from the service with the launch of the Xbox 360.

No, Sony could have implemented cross-party chat, but to do so would have required setting aside memory.  Which, at one point there was more than enough reserved for the OS to do so.  However, Sony weighed the benefits of giving gamers cross-party gaming, or giving developers more memory for games.  They went with the latter, reducing the amount of memory utilized by the OS to 50MB from 120MB.  Had they believed gamers would have wanted cross-party chat over better games, they would have gone with the former.

You're looking at the situation from hindsight, and they didn't come to that decision in hindsight.  Just like the removal of backward compatibility Sony made a concious choice to not do something because the PS3 was such a badly architeched device.

People can argue that the Xbox 360 had the RRoD, but the RRoD could be engineered out of the Xbox 360 with a few modifications and reducing the die size and power consumption.  The PS3's problems couldn't be engineered out because they were intergral to the nature of the device.  The poor design and planning of the PS3 is something that isn't debateable.  It's what it is.