1) They believe that quantity is easier

The practice of going for multiple links was a way of building authority initially. Marketers did this using various tools and tactics, so doing they were able to grow low-quality links in large quantity. They had high rankings, but as Google improved their algorithm and technology, the story has changed.

The ranking has now changed from lots of irrelevant links to high-quality links. The focus has shifted from gathering lots of links in a short time to acquiring links from trusted websites. Getting a link from a trusted site is worth a lot more than acquiring lots of links from low-quality sites

2) Lack of a laid down SEO Strategy

Just like any other business, planning is very important when building your dream website. Many don’t plan out how they intend to go about their Search Engine Optimization (SEO). You should decide on how you want to get content for your website. Are you going to dedicate some time to writing, or are you hiring a writer? What tools are you going to use?

This and lots more should be in your SEO plan.

3) Buying backlinks

Yes, I agree with you, buying backlinks will save you a lot of time and effort. But you will get your fingers burnt. Google refers to this as link schemes. You won't want to be caught cheating. Your website will be penalized and this could mean starting all over again.

You should avoid websites that will sell links for some cash. A lot of them are out there. Google’s algorithm has improved, and you cannot win with this for long.

4) Lack of Patience

Many marketers are out there displaying how they built houses on the sea within one week. But building a sustainable business will take time. If you build quality backlinks to your website, it will take some time, and you need to follow the books.

Like I emphasized, initially when building links, we should go by the books. Having an insight into some relevant tips for building backlinks will a good idea