It also prevents you from making the #1 noobie mistake, which is buying in the hood just because it's cheap.

Here's an example why:- One of our people made a mistake last year, and entered an expense of $1500 instead of $150 - they accidently typed an extra "0". - Fortunately, our transparent systems allowed the owner to catch it:)- Full transparency - we would have never caught this honest mistake:(An owner also needs to be involved to approve & fund large expenses: maintenance, property tax & insurance payments (if they want to be more hands off), evictions, etc.A great PMC should also have a chat with you annually about your future plans for a property and your portfolio. 

If you hire a PM, your financial account structure can be simpler.If you plan to continue purchasing rentals, I like some key accounts at the "management" level (income, opex, tax, owncp, reserve) and only have 1 checking account per property to prevent having 100 accounts and unnecessary complexity.

The more rehabs you do the better understanding you will have of the market for contacting work and materials.Doing a rehab every so often prevents you from being sharp with your budget.For those with limited exposure, ask others in the industry and always run your numbers based on being overbudget and overtime. 

What prevents them from doing that?

Many people have limiting beliefs, a mental barrier that prevents someone from achieving their goals or living fully, so they sabotage any hopes of progress through words or actions.

Quote from @John Underwood: LOLI'm certain they will add restrictions to prevent people from doing this.

I applied for a HELOC and when they ran the title it came up that the 8k grant is actually a second "soft" lien against my property that will go away after 5 years which prevents this bank from allowing me to have a HELOC.

I believe it tends to give me a slightly lower return, because the sponsor is going to be more careful, and if there is a severe downturn will prevent me from taking catastrophic losses.

Might prevent him from buying another home for several years.