He probably alienated the head scouts because he was getting a load of bargain bin rubbish. De Jong & De Ligt may have been a stretch, but the level of players we signed under Poch was pitiful. Here is Nkoudou, Janssen and Sissoko, now go win us a title .. yeah right. As for him alienating the scouts being why we signed nobody, we failed to get the likes of Grealish over the line.
He can. All coaches have a right to ask for players that fit the style. I highly doubt Poch was limiting his options to the top tier, but likely just didn't want more trash to fill the squad. He wanted quality, and aside from a couple of signings we weren't offering that.
If the critique is 'he wasn't perfect, but was still fucking brilliant' then sure, it's valid. If it's suggesting he did an under par job with us, it's utter nonsense and not worth reading. Man got us top 4 season after season during our austerity years and delivered us a CL final with a side which was lucky to get out the groups.