Why Not Templates?
Uniqueness and Originality
Obviously the templates are popular, that's what the providers claim on their websites too. It would be true, but in this case, your website will lose its uniqueness. How would your design stand out, If every second website your customer browses looks similar? How will you cut through the clutter, if you lack originality/uniqueness? A unique website is always judged by its layout. If the layout is common, it doesn't attract the visitors.
Limited Customisation
The templates are rigid, you can't do too much of customisation on a template. The options are limited, what best you can do is to change text or image. Not to mention, majority of the templates look more or less the same.
SEO challenges
I have seen many issues in terms of SEO, somehow Google doesn't like the template sites. For instance, the most popular WordPress sites are hard to optimize for the Search Engines. How many times have you landed in a templated website while you were searching for some information on Google?
Performance
Be ready to take the beating in terms of loading speed. As it is a template, you are bound to have many lines of unwanted codes, which will affect the performance of the site. Many people ignore performance, no user likes waiting. It's high time you realise, performance is equally important as look and feel.
Adaptability
Would you like to stick to your brand guidelines and build a website which depicts what your company stands for or make adjustments based on some plug and play template, which was built for thousands of lazy customers? Do you really want to compromise?
Scalability
As I mentioned earlier, this medium is ever evolving. You might want to add more features at a later stage or move to a powerful server. Data migration can get quite tough. Many template server providers don't support this. So choose wisely, better safe than sorry.
Cheap
Here comes the biggest trap. Do you really think you can customise the theme without coding knowledge? Not really, you have to invest time or money to learn how to code a webpage or hire someone to help you. The moment you start adding your own graphics and content, the template is likely to break. Sometimes you will realise that you want to scale or add a new feature and you might have to put the entire template site into the trash and build from the scratch. Is it really cheap? It is really not when you think long term. And yes templates are cheap because they look cheap :)Everybody wants freedom and fights for it. If you are ready to be caged then you can go ahead with a predefined template. You may feel suffocated at times. Today, all the products are evolving; you might like to add a new feature to the site. What if the templates are not providing the option? Would you go ahead and rebuild a new site?If you have limited budget and are looking for a quick rollout, you might consider templates. But again, would you want a site that is not easily findable on Google?Simply put; if you have a business that can make money, find a good developer. The cost will be negligible compared to the return. If you don't have a serious product or your living does not depend on it then go ahead with a template.