@Ali L.. I see you might be in Brooklyn so definitely verify what I'm saying. In principle, each country has similar programs, but the details may differ somewhat.
The rule of thumb, is anytime there is a government benefit available, you should try and take advantage of them. The benefits usually come in 3 forms. Tax Deductible, Tax Deferred, or Tax Free and usually, you can have one of the 3. Very few things in the world will have more than one. If so, you should focus your energy on those items.
In Canada, an RRSP is one of those items. You get a tax deduction (as a Permanent Resident / Canadian Citizen) and tax deferred growth while the money is in there. Being that you didn't pay taxes on the money when you put it in an RRSP (hence the tax deduction). If you take it out of an RRSP, you kind of owe the taxes on the money that you didn't pay. This is where the first time homebuyer (FTHB) program is super useful. You can take up to $35,000 out of an RRSP without having to repay the taxes (that you're suppose to have paid originally but didn't) hence it is not a grant but rather an option to give you the flexibility of buying a home. This is why you are required to repay the money back over 15 years.
Now, having said the above to address your question about it not being worth it... let me put the numbers in perspective. Using $35,000 because that is the limit to the FTHB program.
In order you to have $35,000 in cash, you would have had to make $50,000 in income (assuming a 30% tax rate) the government took $15,000 in taxes. Now if you used the $35,000 as downpayment, you would have $35,000. If you take that same $35,000 and put it into an RRSP, you would have $35,000 downpayment, plus the government would give you back $15,000 as a tax deduction. This means you would now have $50,000 to put against your house which gives you a lot more buying power.
Obviously the above example is overly simplified, but if you understand the principle that I'm trying to show, you'll understand why its is such a great strategy.