Since those with great stats are more likely to do things that their great stats call for they are specifically not engaging in role play and earning Inspiration. They're just doing what the data says, that's roll play.
Er...what? Are you seriously saying that
because a PC has high numbers, the player is not going to roleplay as frequently?? What prevents "doing things related to your high stats" from being excellent roleplay as well?
Low score characters that succeed are going to have to do things in the social and exploration tiers that the high stat player is more likely to ignore, because "The whole rationale for a player having a PC, in my view, is to be able to engage in conflict as the core of play."
Why would
any player--regardless of the character's stats--ignore a built-in, ready-made, and (fairly) easily-obtained bonus? Even with high stats, there is (almost) always a chance of failure, so even from a "rollplay" standpoint (and you should know that most people consider that an insult) there's no reason
not to seek Inspiration. The low-stat character may
need Inspiration to have a hope of success, sure, but both of them definitely will
want it.
And, again, I completely fail to understand how high stats--whether point-bought or rolled--will make it
harder to roleplay. I'm going to roleplay my character the way I roleplay it regardless of its stats, though the pleasure I derive from play
may be affected by how often I can succeed, which
is affected by stats.
Personally, I see rolling vs point buy to be indicative of playstyle more than anything else.
It boils down to, do you look over at the muscular jock over there and think to yourself, he must be about as strong and fit as I am smart and wise. Or do you think, maybe some guys get all the luck, and maybe I'm okay with having a few points more or less overall, because it's what I do with what I'm given that matters.
I've...never thought that in my entire life. Usually, when I look at someone physically fit, I think, "Ugh, I wish I had the patience, endurance, and gumption to work out so I could look like that." I know I'm no slouch when it comes to the cranium, and I
could get such a physique too, I'm just not motivated enough.
Also: did you mean to imply that most/all people who prefer point buy are "immature" gamers with an "entitlement complex"? And that "expecting a PC to last" inherently means the DM pulling punches? Because the first is pretty blatantly insulting, and the second would mean you aren't very good at accepting others' gaming preferences, neither of which I think you actually
want to communicate.