Blocker entities are purely for "bypassing my local laws and country from make sure I follow said laws".
Sure, I understand the appeal - it's the equivalent of hiding a bag of cash somewhere and having a trusted third-party provide the location to whoever you want after your death. No laws, no lawyers, security for your wishes - exactly what you want.
"Tax issues" are synonymous with "I'm liable to pay more taxes if I'm up-front, direct and transparent with my legal structure"
That isn't entirely true. For instance, if you are investing on behalf of a foundation or other nonprofit structure, or a similar non-taxed or tax-deferred entity (like a pension fund), you have a reason to preserve your legitimate tax free status. This is one reason you'll see US hedge funds with both Delaware and Cayman entities even if they only have US subscribers - because some of those US subscribers will be entities outside the conventional person/corporation tax model.