Who is down on Rizzo? I think he should in the 2 because of his walks. There are articles about putting one of your best hitters in the 2 spot. Rizzo power is not as high as Baez and Bryant. Rizzo has his issues that numbers do not say. His BABIP is low because he doesn't make hard contact consistently. He rolls over and pops way to much for his BAPIP to normalize. Rizzo should be looked as the next LaRoche with still a ton of potential. Not everyone is a star. Castro has proven himself numerous seasons. Rizzo hasn't. I don't know how people worry about Castro more. Castro was changed by staff to be a completely different hitter. Rizzo was not. Rizzo has problems but I don't think he cant fix him.
Now, for people relying on Olt. I would get over that. The guy has serious issues. Hope he works out of them but even if he gets back. He still would have issues.
The media I guess in ref to who's down on him. As for his line up position, you typically put a guy with better speed in the 2 hole. If you're going to rely on his OBP maybe put him in the 3 hole with presumably Baez and Bryant in the 4/5 holes.
I assume you're talking about Adam LaRoche as the other has no where near the numbers. If so I'd say he's already that good.
LaRoche's average season - 73 runs 25 HRs 86 RBI 9.7% walk rate, 22.2% K rate .210 ISO .305 BABIP .264 avg .336 OBP .475 SLG .346 wOBA 111 wRC+
Rizzo this season(with 26 games remaining) - 64 runs 21HRs 72 RBIs 11.4% walk rate, 18.6% K rate .197 ISO .255 BABIP .232 avg .326 OBP .429 SLG .330 wOBA 105 wRC+
So, I think the floor on Rizzo is LaRoache. His upside is harder to project. There's not a lot of power hitters who have a 11.4% walk rate. It's not too bold to suggest that Rizzo could easily develop into what Bautista is doing this year. He's currently at 82 runs 28 HRs 73 RBIs 13.1% walk rate 15.9% K rate .239 ISO .259 BABIP .259 avg .358 OBP .498 SLG .371 wOBA and 134 wRC+. If so, that basically would make him a top 15 power hitter in the league. It's a relatively short jump from where Rizzo currently is to those numbers.
As for Castro... I guess I'm just not that impressed. His average season thus far has been 66 runs 8 HRs 53 RBIs 5% walk rate 15.1% k rate .122 iso .324 BABIP .284 avg .323 OBP .406 SLG .318 wOBA 94 wRC+. Historically he's been a below average fielder(-10.7 Fld) and a slightly below average base runner(-1.7 BsR). Those numbers are basically Yunel Escobar or Eric Aybar only as a worse fielder. That's not to say those are bad players. But, they aren't exactly stars either. Also, there's not a ton of reasons for optimism that Castro will be better than that. And its not even like he can fall back on his fielding as that has been poor this year too.
If you're going to play Castro at 2B instead of Barney he's possibly a decent 2B who's cost controlled and you would expect his defense to matter less there. But honestly, at this point if I could get a potential #1 or #2 starter prospect for him I'd take it because there are guys in the system who probably as much potential at 2B as he does.