While Mawlana's reasons are understandable, although by no means conclusive to obligate it on the entire Ummah, it does not stop there. For the vocal propogators of Taqlid Shakhsi in our times not only obligate it on the awwam to stick to Muftis of a particular madhhab, but they often criticize the scholars of the school for teaching other than certain specific opinions (muŽtamad, mash'hur etc). While it may be wise for the masses (non-scholars, non-students) to do such a rigid Taqlid for the reasons that you quoted, but surely accusing not only the awwam, but also the ulama of the dhahir and batin of lacking sincerity etc. are very dangerous accusations. So surely those are not reasons for obligating Taqlid Shakhsi on Tullab and Ulama, yet scholars not following the standard textbooks are shot down within seconds.
As for the nafs, I find some "super-shakhsis" bringing that out of themselves too. Their Hanafism or Malikism etc. becomes a matter of the nafs. Surely that is equally detrimental. Also... How does transgressing the limits of the shariŽah, opposing ijmaŽ etc. come into play if you do Taqlid of the Mujtahid Imams, but not sticking to a specific madhhab? There is a difference between following different Mujtahids and an illiterate farmer doing his own ijtihad and extracting rulings from the sources.